Why do my WinForms controls flicker and resize slowly?

Question

I'm making a program where I have a lot of panels and panels in panels.

I have a few custom drawn controls in these panels.

The resize function of 1 panel contains code to adjust the size and position of all controls in that panel.

Now as soon as I resize the program, the resize of this panel gets actived. This results in a lot of flickering of the components in this panel.

All user drawn controls are double buffered.

Can some one help me solve this problem?

Answer 1

To get rid of the flicker while resizing the win form, suspend the layout while resizing. Override the forms resizebegin/resizeend methods as below.

protected override void OnResizeBegin(EventArgs e) {
    SuspendLayout();
    base.OnResizeBegin(e);
}
protected override void OnResizeEnd(EventArgs e) {
    ResumeLayout();
    base.OnResizeEnd(e);
}

This will leave the controls intact (as they where before resizing) and force a redraw when the resize operation is completed.